The Taboo Of Not Subscribing To Anthropological Global Warming

[loafer]

Thanks.

The Three Degrees section appears to contradict the use of 4.2 degrees, vis;

Three degrees as the consensus estimate

A committee on anthropogenic global warming convened in 1979 by the National Academy of Sciences and chaired by Jule Charney^[10] estimated climate sensitivity to be 3 °C, plus or minus 1.5 °C. Only two sets of models were available; one, due to Syukuro Manabe, exhibited a climate sensitivity of 2 °C, the other, due to James E. Hansen, exhibited a climate sensitivity of 4 °C. "According to Manabe, Charney chose 0.5 °C as a not-unreasonable margin of error, subtracted it from Manabe’s number, and added it to Hansen’s. Thus was born the 1.5 °C-to-4.5 °C range of likely climate sensitivity that has appeared in every greenhouse assessment since..."^[14]

Chapter 4 of the "Charney report" compares the predictions of the models: "We conclude that the predictions ... are basically consistent and mutually supporting. The differences in model results are relatively small and may be accounted for by differences in model characteristics and simplifying assumptions."^[10]

The 1990 IPCC First Assessment Report estimated that equilibrium climate sensitivity to CO₂ doubling lay between 1.5 and 4.5 °C, with a "best guess in the light of current knowledge" of 2.5 °C ^[15]. This used models with strongly simplified representations of the ocean dynamics. The IPCC supplementary report, 1992 which used full ocean GCMs nonetheless saw "no compelling reason to warrant changing" from this estimate ^[16] and the IPCC Second Assessment Report found that "No strong reasons have emerged to change" these estimates^[17], with much of the uncertainty attributed to cloud processes. As noted above, the IPCC TAR retained the 1.5 to 4.5 °C, and the AR4 tightened it slightly to 2 to 4.5 °C with a best estimate of about 3 °C.

In 2008 climatologist Stefan Rahmstorf wrote, regarding the Charney report's original range of uncertainty: "At that time, this range was on very shaky ground. Since then, many vastly improved models have been developed by a number of climate research centers around the world. Current state-of-the-art climate models span a range of 2.6–4.1 °C, most clustering around 3 °C."^[9]

^{Any idea why such a high figure was used, when it contradicted the "agreed consensus"?}

[songster]

Because Hansen was writing a paper about his climate model, which happened to show a climate sensitivity of 4.2 degrees. As you quote, this was one of two models that collectively defined the agreed consensus, and at the time it was not known which model was right. In the 20+ years since then, it's been shown that the truth most likely lies somewhere in the middle, but higher climate sensitivities are not yet ruled out. Basically, it boils down to how much sulphate aerosols China has been emitting, and how much those have held global temperature down in the last decade or so.

Note also that in the very first paragraph describing the model (in the 1988 paper), you find this section:

"The equilibrium sensitivity of this model for doubled CO2 (315 ppmv -> 630 ppmv) is 4.2°C for global mean surface air temperature (Hansen et al. [1984], hereafter referred to as paper 2). This is within, but near the upper end of the range 3° ± 1.5°C estimated for climate sensitivity by National Academy of Sciences committees [Charney, 1979; Smagorinsky, 1982], where their range is a subjective estimate of the uncertainty based on climate-modeling studies and empirical evidence for climate sensitivity."

It's hardly some kind of grand conspiracy given that the very first act when discussing the model is to discuss the then-existing disagreements over climate sensitivity! Moreover, the sensitivity is an output of the model, not an input - it would be utterly wrong for him to arbitrarily pretend that his results didn't give a figure of 4.2 degrees.

Edited February 17, 2012 by songster

[VillagePlank]

http://www.realclima...ta-comparisons/

Covers this quite nicely. The 1988 Hansen paper used a value of 4.2 degrees C for climate sensitivity - it's now believed to be about 3 degrees C. Once you adjust for this, the forecast agrees with measurements to within the limits of accuracy. Note that in the real world, emissions have been running slightly below Hansen's scenario B in the 1988 paper.

Yes, I quite agree, but this seems to be some sort of inverse fallacy of composition argument.

My point is that (in this order)

(i) We find the laws of physics

(ii) we construct computer models for (i)

(iii) We extrapolate (ii) into the future.

No one (as far as I can tell) is even pretending that we are going to be able to predict that, in Britain, the year 2025 will post a CET value of 10.0C. I don't even think people are pretending that we can do it for the world, either - since the Navier-Stokes equations can only be generally solved approximately you'd need an infinite amount of computing power to be certain of such a thing.

Back to my point: which one of the three steps will have to change for people to change their mind? Of those that I have listed, only one can change and that's the first one; which implies that one can only change their mind if one changes the laws of physics. Of course, I have left out a crucial step (for simplicity) and that's the parameterisation of the models - which is the bit that does change.

I quite accept that as a general ensemble all the models point to temperatures doing one thing: going upwards - and yet they all, it seems to me, missed the rapid reduction in temperature increase seen between 2000-2010. That's decadel variation and, in my view, that's quite a serious indictment. Particularly, as the laws of physics have yet to change. Yet.

Given a presumption that we are all not idiots, I must conclude that since the laws of physics haven't changed, it must be the models with the tinkering of the parameters that changes here in combination with an increase in computing power and reduction in scale.

Whether or not that's a good thing is up for debate, of course!

Edited February 27, 2012 by Boar Wrinklestorm

[Devonian]

Yes, I quite agree, but this seems to be some sort of inverse fallacy of composition argument.

My point is that (in this order)

(i) We find the laws of physics

(ii) we construct computer models for (i)

(iii) We extrapolate (ii) into the future.

No one (as far as I can tell) is even pretending that we are going to be able to predict that, in Britain, the year 2025 will post a CET value of 10.0C. I don't even think people are pretending that we can do it for the world, either - since the Navier-Stokes equations can only be generally solved approximately you'd need an infinite amount of computing power to be certain of such a thing.

Back to my point: which one of the three steps will have to change for people to change their mind? Of those that I have listed, only one can change and that's the first one; which implies that one can only change their mind if one changes the laws of physics. Of course, I have left out a crucial step (for simplicity) and that's the parameterisation of the models - which is the bit that does change.

I quite accept that as a general ensemble all the models point to temperatures doing one thing: going upwards - and yet they all, it seems to me, missed the rapid reduction in temperature increase seen between 2000-2010. That's decadel variation and, in my view, that's quite a serious indictment. Particularly, as the laws of physics have yet to change. Yet.

http://www.realclimate.org/index.php/archives/2012/02/2011-updates-to-model-data-comparisons/

[VillagePlank]

http://www.realclima...ta-comparisons/

"As we stated before, the Hansen et al ‘B’ projection is running warm compared to the real world (exactly how much warmer is unclear). As discussed in Hargreaves (2010), while this simulation was not perfect, it has shown skill in that it has out-performed any reasonable naive hypothesis that people put forward in 1988 (the most obvious being a forecast of no-change). However, the use of this comparison to refine estimates of climate sensitivity should be done cautiously, as the result is strongly dependent on the magnitude of the assumed forcing, which is itself uncertain. "

This is better, though.

Edited February 29, 2012 by Boar Wrinklestorm

[summersnow]

For me, not agreeing with hypotheses around AGW is about having equally rigorously scientifically-based alternative theories that stack-up. Not much of that about as far as I can see - just lots of sniping and disingenuously picking selective holes in the existing theory. If there was another theory that was demonstrably able to show that AGW was nonsense - then all of the scientific community would have to sit-up and take notice and accept the new theory(ies). That's my understanding of how science works. Call me niaive....

[summersnow]

For me, not agreeing with hypotheses around AGW is about having equally rigorously scientifically-based alternative theories that stack-up. Not much of that about as far as I can see - just lots of sniping and disingenuously picking selective holes in the existing theory. If there was another theory that was demonstrably able to show that AGW was nonsense - then all of the scientific community would have to sit-up and take notice and accept the new theory(ies). That's my understanding of how science works. Call me niaive....

Yes.. probably a little niaive! There are several other theories that abound but unfortunately are given no credibility through the orthodoxy of AGW science...primarily because the peer review process is contolled by proponents of the mainstream theory! T'was always thus in science and t'will remain so long as scientists have agendas. Please don't tell me scientists don't have agendas, otherwise I will be forced to use a different adjective to niaive! Edited February 29, 2012 by summersnow

[BornFromTheVoid]

Yes.. probably a little niaive! There are several other theories that abound but unfortunately are given no credibility through the orthodoxy of AGW science...primarily because the peer review process is contolled by proponents of the mainstream theory! T'was always thus in science and t'will remain so long as scientists have agendas. Please don't tell me scientists don't have agendas, otherwise I will be forced to use a different adjective to niaive!

So there will be no presenting peer reviewed evidence to you so... what type of evidence do you accept then?

[Thundery wintry showers]

Although there is certainly some evidence of defensiveness over the scientific "consensus" I think climate scientists on the whole are more inclined to allow expression of alternative viewpoints/theories than most. After all, climate science should be about the quest to identify the truth so if the genuine sceptics can come up with scientific evidence that casts doubt on some aspects of the prevailing consensus, then it forces scientists to re-assess the situation and improve their understanding of the global climate system. Indeed a number of established climate scientists have actually said to me that they welcome having their positions questioned using scientific counter-evidence.

The real problem is when it gets political, when "is indicated if current trends continue", "is statistically likely" and "has 80% support from the multi-model ensemble" get replaced with "will", "will" and "will", and "alternative viewpoints will be considered if supported by sound scientific evidence" gets replaced with "either you're with us or you're against us- we all need to speak with one voice and, because many people don't understand probabilities we need to make it clear that the science is settled even though it isn't".

[Methuselah]

Yes.. probably a little niaive! There are several other theories that abound but unfortunately are given no credibility through the orthodoxy of AGW science...primarily because the peer review process is contolled by proponents of the mainstream theory! T'was always thus in science and t'will remain so long as scientists have agendas. Please don't tell me scientists don't have agendas, otherwise I will be forced to use a different adjective to niaive!

Unfortunately, most - if not all - of these other 'theories' are nothing more than conjecture. What's more, they're seldom in line with the evidence. I am a natural-born sceptic; even more so when Big Oil or Coal come up with 'theories' that seem only to justify the continued exploitation of fossil fuels - and those interests' continued profits??

[summersnow]

Unfortunately, most - if not all - of these other 'theories' are nothing more than conjecture. What's more, they're seldom in line with the evidence. I am a natural-born sceptic; even more so when Big Oil or Coal come up with 'theories' that seem only to justify the continued exploitation of fossil fuels - and those interests' continued profits??

Not true! There are several very plausible theories that are simply not getting any air time because the peer review & publicity processes are so well sown up by the IPCC et al. Worse still, alternative theories are seriously maligned purely, simply because they challenge mainstream theory!

History will tell you that any version of the past is told according to the views of the story teller. That is why, we have so many very different accounts of historical events - those who have the power, basically control what becomes the most accepted version of events. This is also what also happens in science, politics, academia, law or virtually any walk of life conceivable. The "truth" is just a sideline - much more important is whose theory, team, party, gossip, arguement, sex appeal, charisma, movement, morality etc, is winning! Reputations, egos, money, power, greed, self /territorial protection/promotion....., all get in the way of establishing the truth clearly. As I stated before..."t'was always thus and t'will always be".....

Oh, and by the way.... there's every bit as much money (probably much more) associated with the funding of AGW research as there is of fossil fuel producers sponsering alternative research. Science is big business these days, and as long as this is the case, the search for the truth through science, will be compromised - be it motivated by politics, power, money or any combination of those!

If AGW theory were to be seriosly challenged, just imagine the fall out! Imagine the egg on so many VIP's faces. Imagine the reputations that might fall and imagine how many people might lose their jobs & livelihoods - not to mention the communities that are sustained by this all important issue?

Don't get me wrong, I am in 100% agreement with the sentimment that the human race is causing massive and possibly irreversible damage to our ecosystems, primarily because there are 7 billion of us on the planet, all competing for twindling resources. I don't however buy the notion AGW science is settled for a number of pretty glaring and obvious reasons.

Edited March 1, 2012 by summersnow

[Methuselah]

I agree with TWS; the problems start when science becomes politicized.

And indeed summersnow, AGW theory is flawed. It being a human endeavour, it is bound to be. IMO all human endeavours are flawed.

But that fact alone does not provide us with any realy coherent alternative??? Where are the credible alternatives to CO₂ induced warming? Surely if there was one WUWT would have found it by now? Once one's discounted all those silly attempts at discrediting the temperature records, that is...

[summersnow]

I agree with TWS; the problems start when science becomes politicized.

And indeed summersnow, AGW theory is flawed. It being a human endeavour, it is bound to be. IMO all human endeavours are flawed.

But that fact alone does not provide us with any realy coherent alternative??? Where are the credible alternatives to CO₂ induced warming? Surely if there was one WUWT would have found it by now? Once one's discounted all those silly attempts at discrediting the temperature records, that is...

I don't think anyone worth their salt who has studied the issue would argue with the theory of "CO2 induced warming"! But the problems start after that - to name but a few....would the 90pp million extra CO2 molecules really be enough to tip the balance? Why are we making assumptions from a period of 30, possibly 100 years of warming within a period of minimum 10,000 years since the last ice age? There is alot of very valid research that complelety debunks the notion that we are now at the warmest point since the last ice age. Why does the recent temperature record nowhere near match the modelled projections? Why does the long term CO2 record always lag the temperature record by some 800 years?

The only bit that makes any sense at all is the theory that CO2 molecules can alter the radiative balance in the atmosphere, but the extra CO2 above what Dr Hansen considers "natural", constitutes such a tiny proportion of the atmosphere, that the effect must be ridiculously marginal. The rest of the assumptions that are made to do with positive feedbacks... water vapour build up, methane release etc, etc are a long, long way from being settled. Because there are so many forces of nature that we are also such a long way from fully understanding, I do not believe the very tenuous science behind this theory to be anywhere near settled - it might be possible, but it's far from settled!

Edited March 1, 2012 by summersnow

[summersnow]

I agree with TWS; the problems start when science becomes politicized.

And indeed summersnow, AGW theory is flawed. It being a human endeavour, it is bound to be. IMO all human endeavours are flawed.

But that fact alone does not provide us with any realy coherent alternative??? Where are the credible alternatives to CO₂ induced warming? Surely if there was one WUWT would have found it by now? Once one's discounted all those silly attempts at discrediting the temperature records, that is...

I do actually believe that the land based temperature record has been seriously flawed, due mainly to land use changes in areas where weather stations are positioned - what is so silly about that? The fact that so much data now needs to be "smoothed" in order to take account of possible contamination of data speaks for itself. If raw data is flawed, then it shouldn't be used - period.

All those theories espoused concerning natural variability, ocean cycles, solar cycles etc all have every bit as much credibility as AGW theory and I do believe WUWT have presented most if not all of those theories. To call those theories "silly", however, is not acceptable until you can provide evidence to support your assertion.

To simply assert that there has not been enough rigour in the peer review process is hollow, while (as I've stated), the peer review process is controlled by those who have a serious interest in maintaining the status quo. As you say.... flawed by the nature of human endeavour!

[BornFromTheVoid]

Summersnow, how about this as an alternative...

The peer review system is in place not just across climate science, but in all sciences, in law, psychology, ethics etc. It is set up to ensure that publications meet a high standard and to try and avoid studies that are illogical, based on erroneous older studies or simply to point out mistakes that the authors may have missed. I'm sure at times people with agendas end up in peer review groups and mistakes get made, but it seems extremely unlikely that every peer reviewer is in on a money making conspiracy in every journal across the world.

A lot of funding is put into climate science because it's seen as a pertinent issue at the moment. Researchers are investigating numerous drivers of out climate including solar activity, changing atmospheric constituents, cloud height and distribution, ocean cycles and so on and so on. As you rightly pointed out, there are 7 billion of us on this little rock, and with around a billion or so starving and more living in poverty, even a small change in climate which could impact crops/food supply could leave a lot more in trouble.

As for our contribution to CO2 levels being so minuscule, think of how little O₃ there is and what a huge effect that has?

The science is not settled. That CO2 is a "greenhouse gas" and causes warming is a fact though, it's just the level of warming due to a multitude of feedbacks that's unknown. Climate science is carrying out so much research because we don't know what's going to happen exactly and uncertainty is a scary thing for many. While the global temperature rise has slowed loads and is below most predictions, Arctic sea ice is disappearing faster than the majority of predictions. All that shows is we have more to learn, hence more research. It doesn't nullify everything.

CO2 lagging behind temperature doesn't mean CO2 can't cause warming. CO2 can be released by oceans as they warm due to other factors, and CO2 can then amplify and spread the warming elsewhere.

For every blog post, anti-AGW book or anti-AGW talk at a conference, there are hundreds of countering pieces of scientific work which supports the current overall consensus that our actions are influencing the climate, through CO2 but many other ways also.

This most likely isn't going to alter your opinions on the subject, but I thought I'd show you another perspective.

[Methuselah]

I really don't have much time for the 'conspiracy' angle that some sceptics seem to introduce...Of course changes in land-use, the UHI effect and so forth have affected raw data; but we all know of that, there's been no attempt to hide it...As BFTV says above: the problems (and there are many!) lie with the feedbacks and not with the theory itself.

In the long run science works like a ratchet; it's forever building on what's gone before. Theories don't become defunct overnight just because all the details are not yet known. IMO, if things were like that science would be no better than a religion. It would all be written on stone tablets, and detractors would be burned as heretics?

If there really are coherent alternative theories out there that explain climate change better than does 'conventional' AGW theory, why does nobody know anything about them?

[summersnow]

I really don't have much time for the 'conspiracy' angle that some sceptics seem to introduce...Of course changes in land-use, the UHI effect and so forth have affected raw data; but we all know of that, there's been no attempt to hide it...As BFTV says above: the problems (and there are many!) lie with the feedbacks and not with the theory itself.

In the long run science works like a ratchet; it's forever building on what's gone before. Theories don't become defunct overnight just because all the details are not yet known. IMO, if things were like that science would be no better than a religion. It would all be written on stone tablets, and detractors would be burned as heretics?

If there really are coherent alternative theories out there that explain climate change better than does 'conventional' AGW theory, why does nobody know anything about them?

You have more faith in science than do I! I certainly don't subscribe to conspiracy theory either but I do understand and recognise the flaws in human nature. In my earlier post, I alluded to why the systems we often regard as sacrosanct are ultimately compromised by people. People have, like any other animal, a built in instict for self protection and this can be exended further in humans to self promotion amongst those who hold sway or aspire to have power and influnece. Most of our systems, in the developed world are therefore corrupt - not due to any conspiracy...just, that's how the world works and always has done.

I am fully aware of how the peer review process is supposed to work, but it just doesn't... or at least it has very limited effectiveness. If you and I develop a theory that is our life's work and which generates funding enough to keep us and all of our associates very nicely, then we will obviously work our butts off to ensure that our little gravy train doesn't get derailed. This isn't conspiracy, it's just good old fashioned survival of the fittest and common sense, dressed up as high brow science.

I also suspect that the vast majority of scientists do actually work in good faith and believe passionately in what they do. But they are also clever, rational people, who understand very well whoever pays the piper, calls the tune, and very few of them relish the prospect of their meal ticket being taken away. I agree that this is most probably true of any profession or walk of life. So, that's when some of our most eminent leaders in the debate go to enormous lengths to ensure that their particular pet theory prevails..such as Dr Michael Mann, doing his littel splicing trick with the temperature record, so that it would match up with the modelled prediction; or why Dr Gleik has acted fraudulently to derail any debate that threatens AGW. I certainly don't believe that either of those scientists are involved in conspiracy, they are just so determined to ensure that their work isn't compromised, that they are prepared to act extremely unethically to achieve their ends. If these are the people along with most of their friends & associates, who control the peer review process within the science of AGW research, what chance of that process being regarded as anything other than a shambles of mutual back scratching?

But, this is nothing new and certainly not the preserve of the scientific fraternity - it happens the world over and unfortunately the more power, infuence and money there is associated with it, the more likely it is to happen.

Science and religion are actually very close bed fellows in the sense that ultimately, they both claim to be the pursuit of the truth. Unfortunately, the messages of both, are all too often corrupted, not by the concept, but by people!

Edited March 1, 2012 by summersnow

[BornFromTheVoid]

Whilst I don't agree with your views here, putting that aside for a moment... couldn't you apply the same logic to all anti-AGW stuff too. After all, they are just humans too, with the intrinsic human flaws you've mentioned.

You're still demonstrating a warped view of the peer review process.

who control the peer review process within the science of AGW research

Each journal has it's own standards and reviewers, in order to maintain a high level of research. It's like you shouldn't go to a qualified, experienced doctor because all the "true doctors" were stopped from making it into the profession by the difficulty of studying medicine!

I tend to have a cynical view of many aspects of humanity, but you appear to be beyond cynical. You cannot apply your logic to only one half of the debate. If humans are controlled entirely by money, then so are both the "alarmists" and the "deniers".

[Devonian]

Summersnow, why doesn't the same human failing you accuse climate scientists of apply to the work you accept from blogs and climate sceptics?

Doh, BFTV beat me to it...

Edited March 2, 2012 by Devonian

[VillagePlank]

The peer review system is in place not just across climate science, but in all sciences, in law, psychology, ethics etc.

Simply not true.

Who tests the climate models? Who does the static analysis of the software? Certainly never seen the results in any journal, and almost certainly never been peer-reviewed by someone who knows what they're doing.

I looked at the latest Gavin Schmidt effort not so long ago. He is still using IEEE floating point numbers (albeit large ones) regardless of the fact that we KNOW that some numbers, for instance 1/10th, cannot be represented by such a scheme. And we KNOW that small and minute changes can vastly affect the outcome. Suddenly any number that is plus/minus a magnitude of ten doesn't look so attractive, does it? Thinking of percentages? You should be.

If you don't believe me - ask the soldiers who died precisely because of such an idiotic error in judgement in the Gulf war.

Perhaps we should indict Oxford University ....

EDIT: see, here, and note - "mathematically, the procedure is unassailable" ie just because the mathematics is right, it doesn't mean the computation is. Indeed,

"Would we be better off if intervals were used for all computations? Maybe, but imagine the plight of the soldier in the field: A missile is to be fired if and only if a target comes within a range of 5 kilometers, and the interval-equipped computer reports that the distance is [4,6] kilometers. This is rather like the weather forecast that promises a 50-percent chance of rain. Such statements may accurately reflect our true state of knowledge, but they're not much help when you have to decide whether to light the fuse or take the umbrella. But this is a psychological problem more than a mathematical one. Perhaps the solution is to compute with intervals, but at the end let the machine report a definite, pointlike answer, chosen at random from within the final interval."

Computer said no.

Edited March 2, 2012 by Boar Wrinklestorm

[BornFromTheVoid]

Simply not true.

Who tests the climate models? Who does the static analysis of the software? Certainly never seen the results in any journal, and almost certainly never been peer-reviewed by someone who knows what they're doing.

I looked at the latest Gavin Schmidt effort not so long ago. He is still using IEEE floating point numbers (albeit large ones) regardless of the fact that we KNOW that some numbers, for instance 1/10th, cannot be represented by such a scheme. And we KNOW that small and minute changes can vastly effect the outcome. Suddenly any number that is plus/minus a magnitude of ten doesn't look so attractive, does it?

If you don't believe me - ask the soldiers who died precisely because of such an idiotic error in judgement in the Gulf war.

Perhaps we should indict Oxford University ....

EDIT: see, here, and note - "mathematically, the procedure is unassailable" ie just because the mathematics is right, it doesn't mean the computation is.

Are you referring to the whole post or just that line BW?

I have no problem with the fact that climate models are imperfect, computers are imperfect, people and thus the peer review system is imperfect.

I'm not trying to argue otherwise so I'm not entirely sure why you directed that at me?

[VillagePlank]

They're not just imperfect - at their core the representation of the mathematics is plainly, and demonstrably, wrong.

It could well be that the answers are still right - but we'll never know, because the idiots who construct these things do not know what they are doing - they have never studied computer science; which, one presumes, is a prerequisite to using computer modelling to construct an argument that guides political policy across the whole Western World and beyond.

EDIT: Sorry in a bad mood today - will keep off the forums ... apologies to all

Edited March 2, 2012 by Boar Wrinklestorm

[BornFromTheVoid]

They're not just imperfect - at their core the representation of the mathematics is plainly, and demonstrably, wrong.

It could well be that the answers are still right - but we'll never know, because the idiots who construct these things do not know what they are doing - they have never studied computer science; which, one presumes, is a prerequisite to using computer modelling to construct an argument that guides political policy across the whole Western World and beyond.

EDIT: Sorry in a bad mood today - will keep off the forums ... apologies to all

I haven't studied computer science so I couldn't really make much of an argument against what you say, though I have a few questions. As the models are just an approximation and the hindcasting attempts to show they do generally work on some level, is it not possible that the scientists know the computers/programmes limitations and do their best despite this? Does the error factor of about one ten-millionth mean the predictions are completely inaccurate, or just off by a few tenths after decades of model simulations?

Otherwise, is there anything you can suggest that might improve the models, other than have them all study computer science?

(Note: If there are any mods reading, there is something wrong with the post editing. Every time I preview this post it keeps throwing in paragraphs and spaces that I don't want, even in the middle of words?)

[VillagePlank]

The technology is out there. See, here, for one example.

Alas, most of the climate stuff is written in Fortran or IDL - which, as far as I can tell, eschew just about every major leap in computer science from the last 30 years (they are used because of their convenience in massively parallel machines (supercomputers) that run these models)

Also, you must remember that an error of 1/10,000,000th is propagated up as each of the 1,000,000,000,000,000,000,000 calculations that make up a point in time and space in a climate model is computed. You don't need to be a genius nor a computer science graduate to see the problem.

Besides, have you ever heard about a minute butterfly flapping it's wings and causing havoc thousands of miles away? Even the smallest of the small ...

The solution is actually quite alarmingly simple. Rewrite these things to use a decimal representation, and use static analysis to prove that it works as designed. I have yet to come across any peer review that demands these things. Oh, and just before I go, use formal methods to specify the software.

If anyone wants a toy project (and knows shed loads about climatology) I am happy to oblige.

The worrying thing is, of course, that we all demand such standards from finanical critical computing, but never from our scientists. Amazing, and I am just as guilty of it as everyone else is - and I (sort of) know what I am talking about!

Edited March 2, 2012 by Boar Wrinklestorm

[songster]

Rewrite these things to use a decimal representation

At which point you can't represent 1/3 accurately, although you can now represent 1/10 accurately.

Pop quiz: Do you think the real world actually uses exact rational numbers?

Edited March 2, 2012 by songster